Sensors are often located outside the ECU (electrical control unit), for example, of a car. Thus, the sensors have to be connected via wires of several meters. These wires are a significant cost factor in automotive systems and further contribute to the weight of the car. Thus, the number of wires to connect a sensor is often limited to the minimum of two lines. These lines are used to supply the sensor and to transmit the data back to the ECU by modulation of the current consumption of the sensor.